Powerful pumps and advanced circulation devices are necessary to keep the water moving in this big aquarium. Pictured is the sump with a 2000 gph Sequence 4600 SEQ22 pump with a Hayward 1.5" actuated ball valve to alternate flow. Also visible is the CO2 tank for the calcium reactor as well as the beginnings of the Chaetomorpha sp. macroalge refugium.